Senior Senate Foreign Relations Committee members aren’t quite sure what to make of the White House’s dramatic shift on North Korea during President Donald Trump’s recent Asia tour. 

Before the president departed on the 12-day trip, he and his senior aides ruled out negotiations with North Korea. But during the Asia swing, he invited the North’s government to the negotiating table, and Trump’s senior staff spoke openly about the president’s terms for the very talks he for months had said would not work.

Trump had threatened Kim Jong Un with the U.S. nuclear arsenal before the trip, but floated the notion while on Asian soil of the duo one day becoming friends.

Why would Kim Jong-un insult me by calling me “old,” when I would NEVER call him “short and fat?” Oh well, I try so hard to be his friend – and maybe someday that will happen!

— Donald J. Trump (@realDonaldTrump) November 12, 2017

The president’s pre-trip threats led Foreign Relations Chairman Bob Corker to hold a Tuesday hearing examining the particulars of a president’s access to the nuclear launch codes. 

The Tennessee Republican and other senior members of the panel, including ranking member Benjamin L. Cardin of Maryland, said they noticed the change in tone from Trump and his senior aides during the trip. But none of the Foreign Relations members said they expect the talk of negotiations with Pyongyang to stick.

“I don’t know that I take anything away yet that I consider to be firm,” Corker said. “I haven’t read a lot into it.”

Watch: Trump’s Return from Asia Could Complicate Tax Cut Plans

During Tuesday’s hearing — which Corker claimed was not specifically about Trump — Cardin characterized Trump’s past threats to “totally destroy” North Korea if Kim attacked the United States or an ally as “frightening.”

But during an interview that afternoon, Cardin told Roll Call that during a White House meeting before Trump departed on Nov. 3, the commander in chief was less hawkish when discussing the North’s nuclear arms and long-range missile programs.

“I think the reality is that what we need in North Korea is an off-ramp to this crisis through diplomacy — working with China, particularly, to change the equation in North Korea,” he said. “I think there’s certainly an avenue there that could be successful. I’m certain his advisers told him about that, and maybe it sunk in. Maybe.”

Asked if he was taken aback by the 180-degree shift during the trip, Cardin described the pre-trip meeting with Trump, during which that “off-ramp” came up.

“He had some of us over to talk before the Asia trip. We made that point. And he was listening. I’m not saying we convinced him otherwise,” the Foreign Relations ranking member said. “I know where his team was. The president has a style I find to be counterproductive, and perhaps he was disciplined on this trip.”

Despite sensing a shift — even if temporary — from the president earlier this month toward preferring a peaceful solution, Cardin raised concerns during the hearing about Trump’s ability to potentially send nuclear weapons toward any foe.

“I would like to be able to tell my constituents and the American people we have a system in place that prevents an impulsive and irrational decision to use nuclear weapons,” Cardin said. “Unfortunately, I cannot make those assurances today.”

One reason is Trump’s ever-changing stances on major issues. And North Korea is no exception.

Amitai Etzioni, a George Washington University professor, said Wednesday that when it comes to the threat from the North’s nuclear weapons and long-range missiles, “Trump is known for consistent inconsistency.”

“Expect that by tomorrow morning, he will be back to saying he will destroy North Korea,” Etzioni said. “He is predictably unpredictable.”

[Trump Mentions Twitter Account With Pro-Roy Moore Posts]

Another of the trip’s curveballs came on the role the Chinese government and President Xi Jinping can play in pressing Kim to give up his nuclear arsenal. Gone were the tough words about China needing to do more, replaced by talk of his friendship with Xi.

“China likes me. China likes me. And I get along with them,” Trump told reporters aboard Air Force One on Saturday. “I do have a very good relationship with Xi.”

“He’s the most powerful Chinese leader since Mao Zedong. And some people say more powerful than Mao,” Trump said Saturday of Xi during a remarkable impromptu gaggle on the executive jet. “With that being said, I really believe he’s a good person, he’s a good man, he wants to do right, he’s representing his people, he’s strong, he’s very strong.”

That kind of “intrapersonal approach” won’t sway Xi to be tougher on Kim, said Etzioni, author of a new book titled “Avoiding War With China.”

“Trump should have offered Xi major concessions for Xi doing something like stopping the fuel,” Etzioni said of Chinese oil exports supplying most of the North’s petroleum needs. “There are a whole bunch of things that would be of very little cost to us. … Trump flattering Xi is not enough while also demanding trade concessions.”

Arizona GOP Sen. Jeff Flake, who, like Corker, is retiring and is a leading Trump critic, furrowed his brow and shook his head when asked about the different tone during the trip.

“I don’t know,” he said. “I just don’t know what to think about it.”

Lawmakers from both parties have been searching for a consistent strategy on the Hermit Kingdom from the White House. Senior Trump aides said just before the trip that their plan was to give recently implemented sanctions ample time to set in, while also pressuring China and other stakeholders to lean harder on Kim’s government.

Corker, Cardin and other members have met privately with senior administration officials to get a sense of Trump’s strategy. Does Corker see a clear vision?

“I don’t know,” Corker said with an animated shrug, his head tilted and an uneasy smile on his face as a door to his fourth-floor Dirksen Building office closed between him and reporters.